The whistling, glistening emerald hummingbirds so familiar in Colorado, the broad-tailed, are not the only hummers of the Colorado summer. The rufous hummingbird has gained a reputation as the “bad boy” of hummingbirds. This copper-colored sprite visits our state only briefly, from mid-July to mid-September, but in that short time the rufous makes its presence abundantly known.
Rufous hummingbirds have the longest migration of any hummingbird. From wintering grounds in Mexico, they move north along the Pacific coast to nesting areas in the Northwest, British Columbia and up into Alaska. In mid-summer they head south again, moving this time along the Rocky Mountains.
Rufous hummers arrive in Colorado and bully the local broad-tailed hummingbirds away from flower patches and feeders they have fed at throughout summer. Despite their tiny size—rufous can be a full inch shorter from bill tip to tail tip than broad-tailed—rufous hummingbirds are extremely aggressive and chase the more docile broad-tails away from food sources. Once a rufous discovers food, it moves in, feeding its fill then taking up a guard post nearby to keep away any interlopers. When a hapless broad-tail whistles in, the rufous hummingbird rockets in to chase away the broad-tail. With its bill in a flower or feeder, eyes looking downward and tail hanging out in the breeze, the unwary broad-tail is a vulnerable target. When that needle-nosed missile, the aggressive rufous, attacks, the feeding broad-tail flees in a panic.
It’s easy to tell the male rufous hummingbird from the male broad-tail, not only by size but by its lustrous copper-orange color, in contrast to the shining emerald green of the broad-tail. Where the broad-tail’s neck, or gorget, is a shimmering magenta, the rufous’ gorget shines a brilliant orange-red. The females of both species are quite similar and difficult to tell apart. Both have green back, buffy-orange sides and tail, and pale underparts with streaking on the throat.
The rufous hummingbird’s antics at the feeder can be great entertainment, proof that tiny size is no limiter to aggression.